MODERN ROAD MAKING.

King Country Chronicle, Volume VI, Issue 450, 23 March 1912, Page 6

MODERN ROAD MAKING.

QUESTION OF PRESERVATION. The preservation of a road after it has been metalled is a question that is claiming a considerable amount of attention from local bodies throughout the Dominion. In our own district, of course, the difficulty to be overcome is the initial work of metalling. However, the preservation uf our roads is a matter of enormous importance particularly in the case of main roads over which a great amount of traffic takes place. The initial metalling schemes which are now being projected and carried out in the district are being done by the ratepayers on borrowed money and any addition or improvement to the ordinary methods which will result in preserving the road for any length of time is naturally deserving of the most thorough investigation by the local authority. In addition to the preservation of the road the improvements hitherto suggested have also the object of cooing with the dust nuisance. In this respect they are of special interest to the town centres where the dust in summer is something of a scourge. The following report by the engineer of the Eltham County Council on the subject will be of interest: "Regarding the experiments I have made with various methods of utilising tar and oi! on the road I am now able to express the following definite opinions Firstly, dealing with oil — this in my opinion, is of no benefit to the roads as a preservative, but is successful as a dust palliative. The method of applying tar to roads which is known to modern engineers as 'tar sealing' is too expensive to be considered. Further, the nature of the stone is such that the tar would nave to be thoroughly boiled before it could be economically used. Of course, it must be borne in mind that the method of applying the tar was primitive, but, granting the use of an up-to-date spraying machine, 1 do not recommend this process. Regarding the treatment known as tar spraying I am very hopeful. A distance of about four chains was treated by painting the surface of the road. Tli6 amount of tar used was two barrels,

the cost of labour being about 10s, making an average cost of about 12s per chain. Again in this instance the method of application was rough and ready. Had the tar been applied under pneumatic pressure by a modern tar spraying machine, I am satisfied the cost would have been reduced by 25 per cent., and a better job made, as the tar could have been projected into the skin of the road instead of lying on the surface only. As it ;s ; the tar has stood for two months of the most trying period of the year and still looks quite good. The road shows a good skin arid there is no dust and no loose stones. Before advising you further on this matter I should like an opportunity of inspecting a machine at work and seeing the nature of the work done. There is a machine working in Wellington and another in Palmerston North. The machines only work during warm weather. Full consideration should be given to this subject, as anything that can be done, within reason, to prolong the life of the main road and relieve the action of the weather and traffic on the road must be beneficial to ratepayers."